It appears that there's a rumor going 'round that Carlos Valdes (Cisco/Vibe) may be leaving The Flash after this season - which would explain the new love interest, Cisco's interest in the meta cure, and his suddenly-revealed desire to marry and have kids.
If true, the part that I'll miss the most is his arguments/banter with Harry (although, with Harry's new personality resulting from the mental reconstruction, they're not guaranteed to continue, anyway). Those two were a tremendous lot of fun when they did that.